Riveting press



25, 1942- J. Q. HOLMES 2,293,824

RIVETING PRESS 4 Sheets-Sheet 1 Filed June 24, 194Q INVENTOR 1942- J. Q. HOLMES 2,293,824

RIVETING' PRESS Filed June 24, 1940 4 Sheets-Sheet s INVENTOR J56 Q/o/mes 75 ATTORNEY! Aug. 1942- J. Q. HOLMES 2,293,824

' RIVETING PRESS Filed June 24/1940. Sheets-Sheet 4 INVENTOR ATTORNEW Patente cl Aug. 25, 1942 i a RIVETING PRESS John Q. Holmes, Anderson, Ind., assigno'r to General Motors Corporation, Detroit, Miclr, a corporation of Delaware Application June 24, 1940, Serial No. 342,105

Claims.

This invention relates to hydraulic riveting presses and more particularly to presses which are adapted for riveting together two parts made of die cast metal, one of which is provided with integrally formed rivets for attaching the two parts together. When securing together two bodies of die cast metal. one of which has integral rivets, it is necessary that the bodies be pressed together with pressure suflicient to assure that the points between the bodies are closed before the rivets are upset. One cannot depend upon the riveting operation for squeezing the bodies together. Difiiculties are presented when attempting to rivet together bodies of irregular shape by means of the ordinary riveting tool.

It is an object of the present invention to provide apparatus for riveting together two bodies, one of which is irregular in shape. More specifically it is an object to provide apparatus for riveting together two die castings which form a part of an automobile horn, this part being the rigid wall of the air compression chamber and a spirally formed air passage and projector or bell which communicates with the air compression chamber. Due to the spiral formation of the air passage, one of the die cast bodies is very irregular in shape. Therefore the present invention aims to provide a number of pressure pads which engage spaced portions of the irregularly shaped body and are caused to apply pressure such as to cause the joint between the two die cast bodies to be substantially closed before the rivets are upset.

A further object of the invention is to provide automatically for the application of the joint closing pressure against the bodies and then for the application of the pressure which causes the rivets to be upset.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 shows a piping diagramfor the apparatus, certain parts of which are shown in vertical cross-section.

Fig. la is a sectional view on line -laia. of Fig. l.

Fig. 2 shows vertical sectional views of the upper and lower dies with the work between also in section. This section being taken on the line 22 of Fig. 3.

Fig. 3 is a plan view of the lower die with the lower die cast body in position thereon.

Fig. 4 is an under side view of the upper die with both die cast members riveted together and located thereon.

5 is a sectional View thru the work and both die members, this view taken preferably on the line 5-5 of Fig. 3.

Fig. 6 is a side elevational view in the direction of the arrow 6 in Fig. 5.

Fig. 7 is a sectional view of the upper and lower die members and the work between them on the line 7-1 of Fig. 3.

Fig. 8 is a side elevation of the two die members looking in the direction of the arrow 8 0 Fig. 3 and is partially broken away.

Referring to Figs. 2 and 4 the upper die cast body 2%! is generally circular in shape, as shown, and provides plane annular surfaces 2| and 22. The surface 2| is to'engage a thin'gasket which, in turn, engages the horn diaphragm. The surface 22 provides a small clearance between the diaphragm and the body 20. The surface 22 merges into a conical surface 23 of gradual slope and the surface 23 merges into tapered surface 24 relatively abrupt in slope. The surface 24 provides the throat or outlet of the air compression chamberbounded on its lower side by the member 29 and on its upper side by the horn diaphragm, not shown. The throat defined by the surface 24 leads into a spiral air passage provided by the channel shaped passage 25a of the upper body 20 and a passage 25%; of the lower body 26. The lower body 26 is shown in Figs. 3 and a. Fig. 3 shows the spiral channel 25b merging into the lower half 2611 of a projector bell. The upper half of this bell is designated as 26a. and is integral with the body 20. The body '26 is provided with apertured ears 27 extending from the exterior walls forming the channel 26a and the bell 26b. Each ear 2'! receives a rivet 28 integral with the upper body 29. Body 20 provides integral rivets 29 extending-from the throat wall 24, defining the throat 26a of the upper body. The portion 26b of the lower body 26 forming a continuation of the throat is surrounded by a wall 2dr: provided with apertures for receiving the rivets 29. The rivets 29 are larger in -diam-' eter than the rivets 28. The flange portion 2|a of the body 20 which provides the surface 21 is joined to the integral upper bell portion 26aby a web 30.

The parts 2% and 26 are loosely assembled and this assembly is placed upon a lower die 3| which comprises abase 32 which is slidable upon a subbase 33 of the riveting press. Base 32 is guided for this sliding movement by bars 34 secured to the sub-base 33 by screw 35. Movement of the base 32 is by grasping a handle 36 attached to the base. As the sub-base 33 may not be wide enough to accommodate all of this movement of the base 32, a shelf 3! is provided in front of the sub-base 33 in order to accommodate the die 3| in the work loading position. The base 32 supports a frame 46 carrying a plurality of hard steel riveting punches 4|, each being located so as to engage an end of one of the rivets 28 or 29. The frame 49 in turn supports a plate 42 shaped to conform to the exterior contour of the die cast body 26, as shown in Fig. 3. Plate 42 may be made in sections and is located by dowels 43 and secured by screws 44.

The base 32 and the frame 69 are provided with a number of vertical bores for receiving and guiding a number of pressure rods. One of these rods 58 is located centrally between the rivets 29 as shown in Fig. 3. The other rods marked 52, 53, 54, 55, 56 and 57 are arranged spirally with respect to the central rod 50. These rods are of different diameters according to the amount of pressure which is required at any point. It appears that rods 59, 5| and 52 are the same size and rod 53 a size larger, 54, 55, 56 and 51 are of the same size but a size larger than rod 53. The upper surface of each of these rods are shaped so as to conform to the surface of the part 26 which the rod engages. The upper surface of each rod therefore provides a pressure pad. In order that the pressure pads will always be in the proper position each rod is provided with a groove 59 for receiving a key 69 as shown in Fig. 2. As the rod 51 is required to press against a substantial portion of the bell 2612 as shown in Fig. 5, this rod terminates in a relatively wide yoke 58 which engages the projector part 26b at all portions of the yoke 58. Fig. 4 shows diagrammatically the different portions of the die cast body 26 which are engaged by the pressure pads of the various rods. The rods are shown by dot-dash circles and the pressure pad 58 by the dot-dash lines. In Fig. 7 the relation of the pressure pad 58 to the bell portion 26b is clearly shown. The means for urging the pressure pad rods 59 to 51 upwardly will be described in detail later, for the present it is suflicient to state that the pressure exerted upon these rods is such as to cause the joint between the die cast parts 28 and 26 to be closed at a time before the rivets 28 and 29 are upset. The area of the pressure pads provided by the rods must be such that undue pressure is not exerted at any point, otherwise the die cast body 26 which is inherent- 1y weak might be permanently distorted and the thin wall of the spiral air passage be disrupted. However, by carefully dimensioning the pressure pads and by providing a sufficient number of them the pressure required for closing the joint between the body and 26 has been distributed in such manner that no part of the castings will be injured. The casting 26 can not slide off from the lower die 3| since its bell portion 26b is retained by a plate 46 secured by screws 41 to a front surface of the base 32 of the lower die 3| (Figs. 3 and 5). After the loosely assembled castings 28 and 26 have been placed thereon, the lower die 3| is moved under the upper die 6| and will be located in the correct operating position relative to the upper die provided the ground surfaces 32a of the base 32 engage the studs 32b (Fig. 3).

of the machine.

The upper die member 6| is secured by screws 62 to a movable plate 63 which is guided on pilot rods 64 fixed to the sub-base 33. The plate 63 is attached to a vertically movable ram 65 of the riveting press which comprises a crank arm articulated with the ram 65. The upper die 6| is provided with a plane surface 6|a for engaging the surface 2| of the die cast body 28. The die 6| carries an insert 66 shaped to engage surfaces 22, 23 and 24 of the body 28. The die parts 6| and 66 therefore back up each one of the integral rivets 26 or 29 of the body 29 by direct contact with the body 20. As shown in Figs. 4 and '7, die 6| supports a plate 61 having a thickness equal to the distance vertically between the plane of surface 2| and the plane of that ear of part 28 which provides the integral rivet 28a shown in Fig. 4. In this way pressure is applied to the ears extending from the projector bell portions 26a and 26b where the rivet 28a passes thru. This portion is near the front edge of the bell portions 26a and 26b. The rivet 28b on the opposite side of the bell as viewed in Fig. 4 is backed up during the riveting operation by the application of pressure to the upper side of the web 30. As shown in Fig. 8, the web 39 is engaged by the inclined surface 68a of an insert 68 fastened to the die 6|.

If, after the dies 3| and 6| are separated, the die casting 29 should adhere to the die 6| it will be ejected by pins 78 urged downwardly by springs 6| (Fig. 2).

Referring to Figs. 1 and 2 the sub-base 33 is supported by a table 19 carried by the frame Sub-base 33 carries pressure rods 12 each having a shoulder 13 for engaging a surface 14 at the upper end of a counterbore in the sub-base 33. The rods 12 are equal in number to the pressure pad rods 5| to 57 and are vertically aligned therewith. In the normal or non-operating condition of the apparatus, the rods 12 will be located with their shoulders 73 bearing against the surfaces M. When the rods 12 are in this position their upper surface engage the pressure pad rods 56 to 51, respectively, in a common plane which is the plane of the upper surface of sub-base 33. Thus it is possible to move the die 3| horizontally out of alignment with the upper die 6| for purposes of loading and unloading the work. The rods 12 are held normally in this position by pistons 15 each engaging a rod 12. Pistons 15 are received by cylinders 16 provided by the table 18 which provides an oil pressure chamber 11 directly communicating with cylinders 16. Chamber communicates with a cylinder 78 receiving a piston I9 extending downwardly thru a packing member 88 and connected at its lower end with a piston rod 8| connected with a piston 82 in an air cylin der 83. Air cylinder 83 is fastened to the lower end of a cup-like frame 84 in turn fastened to a tubular skirt 85 integral with the table 10. The skirt 85 is integral with a partition 86 which is like a web joining the skirt 85 with that portion of the table which provides the walls of the oil chamber 1! and the cylinder 18. As shown in Fig. 1a there are a number of radially extending webs 81 joining the skirt 85 with the wall portion 11a enclosing the oil chamber 11. For clean out purposes the partition 86 is provided with openings 88 which are covered by plates 89 so that the partition 86 and the plates 89 provide a bottom wall of an oil reservoir 98. The normal level of oil in this reservoir is indicated at 9| and is below the lower edges of the webs 81. The level of the oil at 9I is indicated by an oil gauge 92 having a pipe connection 93 extending to a point in the reservoir 99 below the level 9| and having a pipe 94 communicating with the reservoir 90 above the oil level. The reservoir 99 contains the oil for replenishing the oil pressure chamber 1! so that this chamber 11 and the oil pressure cylinders I6 and I8 will always be kept full. Any oil which leaks past the upper portions of the pistons can return thru a common duct 95 which is controlled by a one way check-valve 95 permitting oil to flow only downwardly in the direction of the arrow 91 at a time when the air pressure upon the surface of the oil of the chamber 90 is relieved. When this air pressure is restored by means to be described, this air cannot pass upwardly thru the valve 96 but can cause oil to pass in the direction of arrow 98 thru a check valve 99 and a duct I 99 thereby forcing oil into the cylinder I8 around the piston I9 and thence into the pressure chamber I7 and the cylinder IS.

A source of compressed air is connected by a main air supply pipe NH and a hand controlled valve I 32 with an automatic valve 93. Valve I93 is connected by pipe I l with a duct I95 leading into the chamber 99 between two of the webs 87. In order that the air under pressure coming in at I95 will not create turbulence in the oil in chamber 99 bafile I95 is secured to the lower edges of the webs 8! between which the duct I05 is located as shown in Fig. 10.. These walls 8! are apertured at 81a to provide intercommunication between the spaces between the webs 8?. Valve I93 is connected by pipe I9? with a control valve I98 and by a pipe I99 with a control valve III). Valves I98 and II9 are mounted on a frame II a, of the riveting press and are actuated respectively by rods or plungers Iilfia. and Mia. The plungers I980. and II9a are engaged by adjustable screws I981) and I Ifib respectively carried by a bracket I II attached to the Vertically movable ram 65. When the ram 95 moves to the upper limit of travel the screw I981) engages the plunger IBM to cause such actuation of the valve IBM to cause compressed air to flow therefrom. This in turn causes the automatic valve I93 to operate in such a way as to cut oif the entrance of compressed air thru the pipe I99 and to vent pipe I04 thru pipe I9! thereby reducing the pressure of air within the reservoir 90 to atmospheric pressure. Therefore, after the riveting operation the pressure within the reservoir 99 is relieved to permit oil which has leaked past the piston I5 to return thru the check valve 96. The upper position of the ram 65 is its normal or rest position.

To start the press into operation the operator presses a pedal or lever which trips a one-revolution clutch. As ram 65 moves downwardly valve I98 is permitted to close off the vent pipe Iiil. Valve I93 remains in the status of closing ofi communication between air line I GI and pipe I94. When the ram 65 has arrived at its lower limit of travel the screw IIiBb will engage the plunger II 9a of valve H9 thereby opening that valve. This causes air to rush out of valve H9 and to produce a condition in valve I93 which causes the valve I93 to operate automatically to restore communication between pipe I4 and pipe I'9I. Thereupon the air pressure within the chamber 90 is raised above atmospheric pressure and the oil therein is caused to flow in the direction of arrow 98 thru the check valve 99 in order to replenish the chamber 1! and the cylinders communicating therewith. Obviously this air pressure cannot move upwardly thru the passage because it is prevented by the check valve 96. When the ram 65 has reached its lowermost position the piston I9 will have been forced downwardly by the compression of oil trapped in reservoir 11, until the upper end of piston 19 is about inch above duct I 99. When, at this instant air pressure upon oil in reservoir 99 is restored oil can pass readily around the upper end of piston I9 into the reservoir 99 to replenish the same.

A certain quantity of oil is trapped in the reservoir 11 since it cannot move out thru the check valve 98 and there are a plurality of pistons I5 which efiectively check the flow of oil upwardly from the reservoir 11. The pressure to be exerted by the oil on the pistons I5 is increased by upward movement of the piston 79, this upward movement being eiiected by upward movement of piston 82 which movement is effected automatically by movement of the ram 65 downwardly. For this purpose there is provided a source of compressed air connected by pipe I29, a pressure regulator I2I a coupling I22 carrying an air gauge I23 and a check valve I24 with a compressed air tank I25 within which a pressure of 50 pounds per square inch is maintained. Tank I25 is connected thru a valve I26 and pipe I21 with an automatic valve I30. Valve I39 is connected by pipe I3I with a port I32 in cylinder 83 below the piston 82. For purpose of automatic control of the valve I39, it is connected by pipes I33 and I34, respectively, with valves I35 and I36, respectively, having operating plungers I35a and IBM, respectively, engageable, respectively, by adjustable screws I351) and i351), respectively, mounted on a bracket I31 carried by the ram 65. Valves I35 and I35 are mounted on machine frame Ila. When the ram 65 has reached the upper end of its travel the screw I351) engages plunger I3ta and effects such operation of the Valve I35 as to cause the automatic valve I39 to connect the pipes I27 and I3I. Whereupon air under pressure is admitted to the lower part of r the cylinder 83 thereby causing the piston 82 to move upwardly thereby driving the piston I9 upwardly thereby increasing the pressure of the oil in chamber II so as to cause the pistons I5 to move upwardly and locate the rods 72 in the normal position shown in Fig. 1. During the downward movement of the ram 65, the upper die 6| engages the upper die casting 20 and causes it to push the lower casting 2B downwardly against the pressure pad rods 5I-to-51 and thus cause the rods 72 to move downwardly into the positions shown in Fig. 2. Since the rods I2 are forced downwardly the pistons i5 must move downwardly. As they move downwardly they displace oil which is caused to increase the oil pressure and force the piston I9 downwardly against the pressure of the air forcing the piston 82 upwardly. In this way pressure is applied between the die casting 29 and 26 so as to close the joint between them before the rivets 23 and 29 are upset as the result of the complete downward movement of the ram 95. The oil in the reservoir 71 operates as a medium for distributing pressure to the pistons I5 which are of the same diameter. The pressure which the pistons I5 can exert on the work thru the rods I2 and pressure pad rods 5I-to-5'I is limited by the air pressure in the cylinder 83; By the time that riveting begins to take place the piston l9 will have been moved downwardly untilits upper end is just a little above the port I99 and the piston 82 will be near the bottom wall of the cylinder 83. During this downward movement of piston 82 the air under compression is increased but not to a point as to cause the oil pressure to become excessive.

In the present apparatus, the oil is a medium for distributing pressure to the pressure pads which close the seam between the two die castings. By properly constructing and locating the pressure pads, the pressure applied at various portions of casting 26 is substantially uniform. The pressure applied to the work does not become excessive because it is limited by the compression of the air in the cylinder 83, and that pressure is limited by the pressure in tank I25.

When the ram 65 has reached the downward limit of travel the screw l35b will have engaged the plunger |35a of valve I35 to cause operation of that valve as to automatically effect the master valve 130 and cause the latter to operate to disconnect pressure line I21 from pipe l3l and to connect pipe l3| with atmosphere. The piston 82 thereupon remains in its lower position since it is then nearly down upon the bottom of the cylinder 83. Piston 82 does not return to upper position until the ram 85 moves to its upper limit of travel whereupon the Valve I36 is actuated in such a way as to admit air upon pressure to cylinder 83 and to cause piston '19 to rise to the position shown in Fig. 1, thus causing the rods 12 to be pushed upwardly so that their upper surfaces are in the same plane as the upper surface of the sub-base 33. The riveting press automatically stops with the ram 65 in the upward position so that the lower die 3| may be moved horizontally toward the front of the machine upon the shelf 31 for unloading and reloading.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Apparatus for riveting together two bodies having plane contacting surfaces, anvils for engaging the ends of rivets extending from one body through holes in the other body, means for moving the bodies toward the anvils to cause the rivets to be upset, and means for yieldingly resisting said movement with substantial force to effect, by cooperation with said first means, the substantial closing of the joint between the bodies before the upsetting of the rivets is completed, said second means comprising a plurality of pressure pads engaging different portions of one of the bodies, a pneumatic pressure means for yieldingly resisting movement of the pressure pads during movement of the bodies toward the anvils, and a liquid-pressure means for transmitting pressure from the pneumatic means and distributing said pressure to the pressure pads.

2. Apparatus for riveting together two bodies having plane contacting surfaces, anvils for engaging the ends of rivets extending from one body through holes in the other body, means for moving the bodies toward the anvils to cause the rivets to be upset, and means for yieldingly resisting said movement with substantial force to effect, by cooperation with said first means, the substantial closing of the joint between the bodies before the upsetting of the rivets is completed, said second means comprising a plurality of pressure pads engaging difierent portions of one of the bodies, a pneumatic pressure means for yieldingly resisting movement of the pressure pads during movement of the bodies toward the anvils, and a liquid-pressure means for transmitting pressure from the pneumatic means and distributing said pressure to the pressure pads, means for relieving the pneumatic pressure when movement of the bodies toward the anvils is substantially completed, and means for restoring the pneumatic pressure when movement of the first named means away from the anvils is substantially complete.

3. Apparatus for riveting together two bodies having plane contacting surfaces, anvils for engaging the ends of rivets extending from one body through holes in the other body, means for moving the bodies toward the anvils to cause the rivets to be upset, and means for yieldingly resisting said movement with substantial force to effect, by cooperation with said first means, the substantial closing of the joint between the bodies before the upsetting of the rivets is completed, said second means comprising a plurality of pressure pads engaging different portions of one of the bodies, pressure distributing pistons respectively cooperating with the pressure pads, cylinders for the pistons, all communicating with a liquid containing chamber, a, pressure-applying piston in a cylinder also communicating with said liquid chamber, and pneumatic-means for causing said pressure applying piston to force liquid into said liquid chamber.

4. Apparatus for riveting together two bodies having plane contacting surfaces, anvils for engaging the ends of rivets extending from one body through holes in the other body, means for moving the bodies toward the anvils to cause the rivets to be upset, and means for yieldingly resisting said movement with substantial force to effect, by cooperation with said first means, the substantial closing of the joint between the bodies before the upsetting of the rivets is completed, said second means comprising a plurality of pressure pads engaging different portions of one of the bodies, a pneumatic pressure means for yieldingly resisting movement of the pressure pads during movement of the bodies toward the anvils, means for reileving the pneumatic pressure when movement of the bodies toward the anvils is substantially completed, and means for restoring the pneumatic pressure when movement of the first named means away from the anvils is substantially completed.

5. Apparatus for riveting together two bodies having plane contacting surfaces, anvils for engaging the ends of rivets extending from one body through holes in the other body, means for moving the bodies toward the anvils to cause the rivets to be upset, and means for yieldingly resisting said movement with substantial force to effect, by cooperation with said first means, the substantial closing of the joint between the bodies before the upsetting of the rivets is completed, said second means comprising a plurality of pressure pads engaging different portions of one of the bodies, pressure distributing pistons respectively cooperating with the pressure pads, cylinders for the pistons, all communicating with a liquid containing chamber, a pressure-applying piston in a cylinder also communicating with said liquid chamber, and pneumatic-means for causing said pressure applying piston to force liquid into said liquid chamber, a liquid reservoir in communication with said cylinders of the pressure distributing pistons through a checkvalve controlled drain duct, and in communication with said pressure-liquid chamber through a check-valve controlled replenishing duct, and pneumatic pressure means for causing liquid to flow from the reservoir to the pressure-liquid chamber.

6. Apparatus for riveting together two bodies having plane contacting surfaces, anvils for engaging the ends of rivets extending from one body through holes in the other body, means for moving the bodies toward the anvils to cause the rivets to be upset, and means for yieldingly resisting said movement with substantial force to effect, by cooperation with said first means, the substantial closing of the joint between the bodies before the upsetting of the rivets is completed, said second means comprising a plurality of pressure pads engaging different portions of one of the bodies, pressure distributing pistons respectively cooperating with the pressure pads, cylinders for the pistons, all communicating with a liquid containing chamber, a pressure-applying piston in a cylinder also communicating with said liquid chamber, and pneumatic-means for causing said pressure applying piston to force liquid into said liquid chamber, a liquid reservoir in communication with said cylinders of the pressure distributing pistons through a checkvalve controlled drain duct, and in communication with said pressure-liquid chamber through a check-valve controlled replenishing duct, and

pneumatic pressure means for causing liquid to flow from the reservoir to the pressure-liquid chamber, means for causing pneumatic pressure to be applied above the liquid level in said reservoir in response to movement of said first named means to its limit of travel toward said anvils and for causing said pneumatic pressure to be relieved in said reservoir in response to movement of said first named means to the limit of its travel away from said anvils.

'7. Apparatus for securing together a plurality of body members having plane contacting surfaces with one of the bodies having integral projections extending through and beyond aperture portions of another body member; a holder having a recess for receiving the body members; fixed anvils carried by the holder for engaging the free ends of the projections; reciprocable pressure pads extending through the holder and into the recess for normally holding the body members free of the walls of the recess; ram means for moving the body members in the recess and toward the anvils causing the free ends of the projections to be deformed; fluid pressure means associated with the pads; pneumatic means controlled by the downward movement of the ram for conditioning the fluid pressure means, prior to engagement of the projections with the anvils, for resisting movement of the pads during the initial movement of the bodies by the ram toward the anvils, said pads and ram cooperating for closing the joint between the body members before the deforming of the projections to secure the body members together; and means controlled by the ram for relieving the pneumatic pressure when the movement of the bodies toward the anvils is substantially completed.

8. An apparatus for securing together a pair of body members having plane surfaces; a support for the body membersyanvils carried by the support for engaging integral projections of one body member extending through apertured portions of the other member; holders for the body members reciprocably mounted in the support; fluid pressure means associated with the holders for normally holding the body members free of the support and anvils; ram means for moving the body member toward the support and anvils causing the free ends of the projections to be deformed; fluid pressure means associated with the holders; pneumatic means controlled by movement of the ram toward the body member for conditioning the fluid pressure means, before the projections engage the anvils, for resisting the movement of the holders, said holders and ram cooperating for closing the joint between the body members before the deformation of the projection to secure the body members together; and means controlled by the ram for relieving the pneumatic pressure when the movement of the body member toward the anvil is substantialy completed.

9. Apparatus for securing together a plurality of body members having plane contacting surfaces with one of the bodies having integral projections extending through and beyond apertured portions of another body; fixed anvils for engaging the free ends of the projections; reciprocable pressure pads for normally holding the body members in a predetermined position above and free of the anvils; guide means for aligning the projections with the anvils; ram means for moving the bodies toward the anvils causing the free ends of the projections to be deformed by the anvils; fluid pressure means associated with the pads; pneumatic means controlled by the movement of the ram toward the anvils for conditioning the fluid pressure means, before the projections engage the anvils, for resisting movement of the bodies by the ram toward the anvils, said ram and pads cooperating for closing the joint between the body members before the deformation of the projections to secure the body members together; and means controlled by the ram for relieving the pneumatic pressure when the movement of the body member toward the anvils is substantially completed.

10. Apparatus for securing together a pair of bodies having plane contacting surfaces and having rivets extending from one body through apertured portions of the other body; a series of fixed anvils in registry with the rivets; a fluid chamher; a series of pressure pads controlled by the fluid in the chamber, for normally holding the bodies and the rivets free of the anvils; ram means for moving the bodies and the rivets in one direction so as to upset the rivets and secure the bodies together; pneumatic pressure means controlled by the ram for conditioning the fluid within the chamber, before the rivets engage the anvils, for resisting movement of the pads as the ram engages the bodies and rivets, said pads and ram cooperating to align the rivets with the anvils and to close the joint between the bodies before the rivets engage the anvils; and means actuated by the ram incident to the closing of the joint between the bodies for relieving the pneumatic pressure to prevent the deformation of the rivets; and means for restoring the pneumatic pressure when the ram means returns to its normal position.

JOHN Q. HOLMES. 

